How to create a custom-angled Camera Clipping Plane that only affects Camera Rays?

[d.laurens]

Hi everyone,

I am looking for a way to perform a non-orthogonal clipping in 3ds Max .

The native "Camera Clipping" works perfectly for what I need (objects are hidden from the view but still cast shadows and contribute to the Global Illumination), but it is strictly limited to the camera's Z-axis.

My goal is to align a clipping plane at a custom angle (diagonal or tilted) while maintaining the following behavior:

1. Visibility: Hide geometry between the camera and the clipping plane to see inside the scene.

2. Lighting: The clipped geometry must still be "seen" by the engine for GI, reflections, and shadows (to avoid the interior looking like an open-air scene or having black "hollow" sections).

3. Orientation: The plane should be freely rotatable, independent of the camera's target axis.

Is there a way to achieve this using a specific tool, a modifier or a shader-based approach (like a RaySwitch or Distance map in the opacity slot) that doesn't break the light calculation? ). This would be avery useful tool for managing the complexity of certain viewpoints.

So to resume :

Is it possible to have a clipping plane modifier that can be added to cameras? Is it possible to overcome the limitation of camera clipping parallelism on the z-axis?

Thanks a lot 

Damien

[CAMedeck]

Any chance you're rendering with V-Ray?  There's an object called VRayClipper that will 'hide' parts of your model like a slice or clipping plane.  Better yet, set it to use a custom mesh for even more control.  

[MartinBeh]

In Arnold, there is the clip_geo shader

[d.laurens]

unfortunaltly i'm using only corona and the slicer of corona is quite limited compared to vray clipper . I am indeed using the CoronaSlicerMtl inside a CoronaRaySwitchMtl (Direct visibility only) to keep the GI and reflections of the clipped geometry intact. However, unlike the geometric VRayClipper which has a native "Camera rays only" checkbox, using the Slicer material inside a RaySwitch drastically increases my render times (due to opacity/ray evaluation).  So I find myself quite limited by the native clipping plane system in 3ds Max, V-Ray, and Corona cameras, since the clipping plane is always constrained to remain perpendicular to the camera axis.

Thank you very much for your attention.

Damien

[lauri_barnhart]

Hi @d.laurens, thank you for your question.

Did previous replies by @CAMedeck or @MartinBeh help clarity your question?

If yes, feel free to click on the Accept Solution button.

This helps other users benefit from the information.

In case you still need help, please provide an update here so we can help you best moving forward.

Regards,

Lauri | Community Manager

[d.laurens]

Thank you for your feedback. I did see the answers provided by the two contributors, but as I explained in my last post, they are of no use to me since I work exclusively with Corona Render, and therefore the V-Ray Clipper and Clip-Geo Shader are not compatible with this rendering engine. Corona's other solutions (Ray Switch Material and Slicer Material) are extremely slow (as explained in my last post) and therefore completely unusable, especially on very large scenes with complex materials.

Thank you for your attention.

Damien

[MartinBeh]

Since this is specific to Corona rendering, maybe someone at https://forum.corona-renderer.com/index.php has a suggestion?

[d.laurens]

Thanks for your feedback, Martin. I've already posted about this on the Corona forum (https://forum.corona-renderer.com/index.php?topic=46377.0) , but so far I haven't found a truly effective solution (only through materials, which is unusable for large interior scenes due to extremely long rendering times).
It's because of these difficulties that I was wondering if it might be possible to rotate the clipping plane directly within the camera. This would be a fantastic tool for better image composition and overcoming the parallelism limitation of clipping planes while maintaining rendering speed (as is currently the case with the camera's clipping plane).
Perhaps it's "theoretically" impossible to add the ability to rotate the clipping plane within the physical camera... In any case, it would be a great tool.
Thank you for your attention.

[haifeng_yuSEVKN]

Hello @d.laurens, thank you very much for your post. May I ask whether you have tried contacting Chaos Group for more information? Since it is Corona renderer related, it would be great to contact Chaos Group, they will have a deeper understanding of Corona renderer, as they are the developers behind the tool, making them the most knowledgeable source for insights and technical support. Thank you!

[Casey_H_]

Digging around the Corona forum, I discovered that a clipping plane was on the roadmap ahead of Corona 3 but has since disappeared. The next version is 15 and there is no clipper on the roadmap.

This script claims to add custom clipping controls to a camera, which then allow you to designate near and far OBJECTS as the clip planes:

Object-Bound Camera Clipping | ScriptSpot

Edit: Sorry it still only works with parallel clipping. 😞